The Israel-Iran conflict, long rooted in deep-seated geopolitical, ideological, and strategic rivalries, entered a perilous new phase with the outbreak of open hostilities in 2025. This paper critically examined the implications of the Israel-Iran war on global peace and security, situating the conflict within broader historical tensions, regional power dynamics, and international responses. Drawing on international relations theory, security studies, and empirical developments, the study analyzed the war’s cascading effects across the Middle East, including proxy escalations in Lebanon, Syria, and Yemen, and the broader reconfiguration of alliances involving the United States, Russia, China, and Gulf states. The conflict’s impact on global energy markets, maritime security in the Strait of Hormuz, and the fragile stability of nuclear non-proliferation regimes was also assessed.  The paper explored the weakening of multilateral institutions, the paralysis of the United Nations Security Council, and the erosion of international norms governing warfare. The findings suggested that the Israel-Iran war intensified global insecurities, revealed the inadequacies of existing peace frameworks, and underscored the urgent need for renewed diplomatic engagement and regional conflict resolution mechanisms. In sum, the war represented not merely a regional crisis, but a critical juncture with far-reaching consequences for the international order.